(19)
(11) EP 1 184 854 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
13.03.2002 Bulletin 2002/11

(43) Date of publication A2:
06.03.2002 Bulletin 2002/10

(21) Application number: 01127076.6

(22) Date of filing: 23.12.1996
(51) International Patent Classification (IPC)7: G11B 7/125, G11B 7/006, G11B 7/0045, G11B 11/105, G11B 19/04
// H01S5/068
(84) Designated Contracting States:
DE FR NL

(30) Priority: 26.04.1996 JP 10675296

(62) Application number of the earlier application in accordance with Art. 76 EPC:
96120768.5 / 0803866

(71) Applicant: FUJITSU LIMITED
Kawasaki-shi, Kanagawa 211-8588 (JP)

(72) Inventors:
  • Masaki, Takashi, c/0 Fujitsu Limited
    Kawasaki-shi, Kanagawa 211-8588 (JP)
  • Yanagi, Shigenori c/o Fujitsu Limited
    Kawasaki-shi, Kanagawa 211-8588 (JP)

(74) Representative: Körfer, Thomas, Dipl.-Phys. et al
Mitscherlich & Partner, Patent- und Rechtsanwälte, Sonnenstrasse 33
80331 München
80331 München (DE)

   


(54) Optical storage apparatus


(57) A light emission adjustment processing unit of a laser diode sequentially instructs a D/A converter for light emission of a light emission by test powers at predetermined two points, allows the laser diode to emit the light, instructs a D/A converter for subtraction of subtraction currents corresponding to the test powers at two points, and measures each power by an A/D converter for monitoring. From the measurement results, a relation of the instruction values to an arbitrary power in each D/A converter is obtained by a linear approximation and registered into a power table. When deciding an optimum writing power by a test write, a limit power on the lower limit side is detected while gradually decreasing the writing power from a starting power and a predetermined offset is added to the detected limit power, thereby obtaining the optimum writing power.






Search report